Have some sort of sensor/electrical issue.
I have read about issues of steering shake, or losing power, etc. I have not come across anyone with an issue like mine.
I went out for a little twisty mountain drive and the very turn into the road was wet and i took advantage with some oversteer, slideways fun. (approx 40 mph) Very smooth into and out of the slide, no snapping of the wheel or jerkiness of any kind.
I was about half mile down the road and i had the urge to just do some fast twitches on the steering before entering the twisties. Like some "how are you and how are things" after not driving it for a week.
To my surprise the steering lagged and reacted after my input. very un-s2000 like. i continued to do slalom-like movements and the and it was if the front end was in the air. No resistance, no feedback, but also the steering was delayed.

I pulled into a lot and had the same effects while parked. Mostly occurring in the first half turn of the wheel in either direction.
I turned the car off, sat for a minute. Restarted and steering has been normal since.

Any ideas? Please let me know if you no of the parts needed too.

 

Restarted and steering has been normal since. I think you somehow switched the power steering Off with the steering wheel twitches. I did this one time on a lift by rotating the steering wheel lock to lock several times. I did the reset procedure but yours seems to have reset itself.

-- Chuck

 

and so it never happened to you again?

 

No recurrence -- been at least 5 years since it happened. But I've not thrashed the steering wheel back and forth with the wheels off the pavement again.

I'm thinking these incidents are very similar: Wet road (you) and not touching the road (me) didn't provide much rotational resistance to the steering sensors and the genie under the dashboard shut the power steering down.

-- Chuck

 

thats an interesting theory for sure. Low load during input and the system freaked out?
If nothing else, you've eased my mind a bit, thank you.

 

There may be a caution, official or here, against moving the steering wheel excessively when the wheels are not on the car. Has something to do with the torque sensor on the steering.

Did your EPS light come on?

-- Chuck

 

No light. And my slide was not that dramatic in my opinion. So I think the only factor was the lack of friction. The wheel wasn't whipped violently at all.
your key was on accessory position when it was off the ground?

 

Engine was running with all 4 wheels off the pavement. Part of the winter storage procedure in the owner's manual:While the engine was heating up I would run the car thru all the gears to circulate lubricant in the gearbox and differential. I also manually rotate the front wheels to clean the discs. Stability Assist was Off.

I thought it would be a "good idea" to exercise the steering box at the same time -- wasn't.

-- Chuck

 

Caution needed when car is raised of ground with engine running and manually turning road wheels left to right,it may snatch and trap your hands/arms.
At an MOT test <gov test in UK>and tester got a shock,it nearly got him !!

 

Good caution.

I did this (once!) from the drivers seat using the steering wheel.

-- Chuck